Rehearsal focused purely on blocking, camera positions, and light placement — no emotional acting work yet. Pure choreography for crew logistics.
Before the camera rolls, clarity about space and movement is needed—that's what the Mécanique achieves. You position the actors, show them where to stand, when to move, where the camera follows. No psychological subtext discussions, no long talks about motivation. Pure choreography: step one, step two, the actress stops there, the cinematographer follows, the light cuts off the shadow there. That is Mécanique.
In practice, this usually happens during blocking—but with significantly less emotional weight. You need the movement sequences precisely so that camera, lighting, and editing can plan. An actor who is still unsure also needs this: they know they stand at this mark, that the camera moves back three steps, that there is then room for lighting. This takes pressure off. The felt performance comes later, when the machinery is running—not before.
Where Mécanique becomes critical: when you let it run for too long. Actors who only repeat mechanically lose their spark. You notice it immediately—the movements become sluggish, the gazes empty. That's why experienced directors clearly separate: first Mécanique (30 minutes), then a real run-through with emotions, then—if necessary—a technical fine-tuning. Not the other way around.
Especially with the master shot or complicated multi-camera setups, you almost necessarily need the Mécanique. You have to know if the actor stays in the frame, if the camera can hold their movement, where light cones cast edges. That's why cinematographers and gaffers also do their own dry runs with empty chairs or PAs serving as extras—that's Mécanique for the technical side.
A mistake: misunderstanding Mécanique as a cost-saving measure. If you don't allow the actor a real rehearsal with life because you've calculated the time tightly, it will punish you in the performance. Mécanique is preparation, not a substitute for real work.